The present invention is directed to a part sorting system, and more particularly to a part sorting system for automatically inspecting a plurality of uninspected parts.
Machine vision systems have been applied in a variety of applications, which include food processing, metal recycling, mineral processing and paper recycling, among others. As is well known to one of ordinary skill in the art, vision systems are based on non-contact measurements of electromagnetic radiation (e.g., visible light, infrared light and x-rays), which are typically facilitated by a camera. In the manufacturing and processing environments, it is common to optically inspect and sort individual articles with automatic inspection systems. Many of the inspection systems have determined properties (e.g., color, size and shape) of the articles such that defective articles could be separated from good articles.
Machine vision systems have been utilized, for example, to inspect fruit, vegetables and nuts. Machine vision systems have also been utilized in other areas that require a similar sorting of products and/or articles. For example, such systems have been utilized to sort wood chips, aggregates and manufactured products, such as, fasteners and formed parts, in addition to meat products, such as quartered or cubed poultry or beef products.
In a typical system, video images of the products and/or articles are captured, with a camera and a frame grabber, to extract color, shape and/or size related information. Typically, bulk articles are stabilized, using centrifugal force, and conveyed individually past an optical inspection station. In a typical prior art system that implements air deflectors, the center of a defective product is computed such that an air stream is aimed at the center of the product to remove the defective product from a product stream.
Inspection systems have also been designed to inspect various circular parts by dimension and to detect surface defects in the parts. Some of these systems have determined an inside diameter (I.D.), an outside diameter (O.D.) and detected surface defects, such as nicks, fractures, etc. A wide variety of cameras, which include line scan cameras, area scan cameras and CMOS cameras, have been utilized or proposed for utilization in various inspection systems. Images captured by the cameras are automatically processed and evaluated such that image dependent decisions can be implemented. Typically, prior art systems have performed image capturing on a conveyor belt. Unfortunately, such systems must contend with accumulation of trash on the conveyor belt, thus complicating captured image analysis. Most prior art inspection systems have singulated objects for inspection, which has required additional tooling and has added additional costs to the system.
Thus, an inspection system that performs off-belt inspection and does not require article singulation is desirable.
The present invention is directed to a part sorting system for automatically inspecting a plurality of uninspected parts. The system sorts acceptable parts from defective parts and includes a feed conveyor, a sorting camera, at least one rejection valve and a computer system that includes a processor. The feed conveyor receives a plurality of uninspected parts and distributes and moves the uninspected parts through an inspection area. The sorting camera captures an image of each of the plurality of inspected parts as the plurality of uninspected parts move through the inspection area. The rejection valve functions to redirect a defective part such that the defective part is separated from inspected acceptable parts. The processor is coupled to the feed conveyor, the sorting camera, and the at least one rejection valve. The processor, executing an inspection routine, controls the speed of the conveyor, the scanning rate of the sorting camera and the at least one rejection valve. The processor, executing the inspection routine, also compares at least one edge of a captured image to at least one stored template image to determine whether an inspected part is defective.
In another embodiment of the present invention, a vibratory conveyor distributes the plurality of uninspected parts in a substantially even manner across a top surface of a platform of the vibratory conveyor and provides the plurality of uninspected parts to the feed conveyor. In yet another embodiment, the top surface of the platform is made of a metal that is substantially covered with a material. The material serves to increase the energy absorption and surface friction of the top surface of the platform such that the plurality of uninspected parts are retained on the vibratory conveyor. In still another embodiment of the present invention, the vibratory conveyor includes a plurality of resilient fiberglass legs and an air cylinder. The plurality of resilient fiberglass legs are mechanically coupled to and support a bottom surface of the platform. The air cylinder is mechanically coupled to the bottom surface of the platform and is capable of varying the magnitude and frequency of the vibration of the vibratory conveyor responsive to the processor.